Antidetonating device



v Oct. 25, 1949. s, UDALE- 2,486,228

ANTIDETONATING DEVICE Filed Oct. 13, 1945 INVENTOR.

Patented Oct. 25, 1949 v ANTIDETONATING DEVICE Stanley M. Udale, Detroit, Mich., assignor to George M. Holley and Earl Holley Application October 1-3, 1945, Serial No. 622,133

2 Claims.

The object of this invention is to reduce the knocking of an airplane engine.

The use of an anti-detonating fuel to be used during wide-open throttle is a well-known method of operating an engine.

The drawing shows diagrammatically the preferred form of my invention.

In the drawing, I is the air entrance leading to the carburetor of the variable-venturi type, two throttles l2 and H are geared together by two gears 20 and 22. A smaller gear 24, operated by an operating throttle lever 26, is used to vary the area of the air stream.

A cam 30, mounted on the shaft of the lever 26, engages with the lever 28, which lever 28 moves the needle 32 by means of a tension spring 88, which holds the roller 15 in engagement with the cam 30, so that the needle 32 is opened as the throttles l2 and I4 are openedby the lever 26.

Openings l6 and it are provided for the venting of the throttles l2 and I4, so that the throttles l2 and I4 are more or less aerodynamically balanced and the efiort to move them is not too great. Fuel enters through a fuel venturi 46, flows down a pipe 44, passes an inlet needle 64 and a corresponding inlet needle 66. These inlet needles 64 and 66 are connected to links 96 and 18. The links 96 and 18 are connected to diaphragms 68 and 18 in a well-known manner. The atmospheric pressure is admitted to the fluid is pushed out of the lower part of the tank 60, up through the passage 58, past the needle 56, into the passage 90. A passage 48 connects the throat of the venturi 46 with a chamber 98, which contains a compression spring 16. The chamber 98 is bounded on its right-hand side by the diaphragm 54. The chamber 52, as stated above, is subjected to the full pressure of the gasoline entering the venturi 46, and it is bounded on its right-hand side by the diaphragm 54. Hence, the diaphragm 54 is responsive to the pressure drop due to the fuel flow through the venturi 46. Hence, at high fuel flows, the needle 46 opens and admits anti-detonating fluid from the tank 60, but it is only at high air and fuel flows that anti-detonating fluid is needed. I

Qperation In the normal operation of the carburetor, the

g0 needle 56 is closed by the pressure exerted by variable venturi l2|4. When critical fuel and chambers 12 and 14 through the air vent 82 and the cross-passage 84.

Fuel leaves the fuel chamber 42 through the passage 34 and flows by the needle 32 and flows down the passage 36, which passage is vented at 88 to the air entrance Ill. The fuel that flows down the passage 36 discharges into the throat of the variable venturi formed by the throttles l2 and I4 in a well-known manner and this car- 'buretor is no part of this invention.

The anti-detonating fluid is admitted through a pipe 98, which enters the passage 92. This anti-detonating fluid discharges through the openings 38 and 40 into the throat of the variable venturi I 2-l4. The anti-detonating fluid is contained in a tank 60, but the pressure for the tank 60 is derived from the pressure of the fuel flowing to the venturi 46. A passage 50 is connected to a chamber 52, and the chamber 52 is connected through a passage 62 to the upper portion. of the tank 60. Hence, whatever pressure there may be supplying fuel to the pipe 44 through the venturi 46, that pressure is available for the upper part of the tank 60. The lower part of thetank 60 contains alcohol or other anti-detonating fluid. The fuel in the upper part of tank 60 will ultimately become gasoline, as the anti-detonat ng air flows are reached, the diaphragm 54 moves to the left, the spring 16 is compressed, the needle 56 is opened, fuel flows down the passage into the cross-passage 82 and out of the openings 38-40. Hence, the quantity of anti-detonating fuel supplied depends on the amount of gasoline flowing through the venturi 46, but no antidetonating fluid is supplied until the quantity of gasoline flowing through the venturi 46 exceeds a predetermined critical value.

What I claim is:

1. In a carburetor having a main fuel entrance, means for adding anti-detonating fuel, a source of ordinary fuel under-pressure, a fuel venturi connected thereto in the main fuel entrance to said carburetor, a fuel tank containing antidetonating fuel, a passage connecting the top of the anti-detonating tank to said ordinary fuel pressure line, an outlet from the bottom of said anti-detonating fuel tank, a passage connecting said outlet with the carburetor, a valve for controlling the flow through said passage, a moving wall responsive to the drop of pressure in said fuel venturi, mechanical means connecting said moving wall with said valve whereby said valve opens whenever the flow of the ordinary fuel exceeded a predetermined critical value.

2. In a carburetor having a main fuel entrance, means for adding anti-detonating fluid, a source of ordinary fuel under pressure, a fuel restriction connected thereto in the main fuel entrance to said carburetor, a fuel tank containing antisome detonatlng fluid; a. passage connecting the top of the anti-detonating fluid tank to said ordl- BEFEBBNC ES CITED The following references are 0! record in the file of this patent:

- UNITED STATE PATENTS Number Name Date Re. 22,254 Chandler Jan. 26, 1943 Re. 22,447 Hersey et 'al. Feb. 29, 1944 FOREIGN PATENTS Number Country Date 828,458 France May 18, 1938 

